Automatically variable speed transmission



Nov. 24, 1936. A DE MUYNCK AUTOMATICALLY VARIABLE} SPEED TRANSMISSION Filed Jan. 19, 1955 2 Sheets-Sheet 1 m4 wM I IIIIII/ fill NOV. 1935- A. DE MuYNcK 2,061,367-

AUTOMATICALLY VARIABLE SPEED TRANSMISSION Filed Jan. 19, 1935 2 Sheets-Sheet 2 V v the radial position.

Patented Nov. 24, I936 PATENT OFFICE AUTOMATICALLY VARIABLE SPEED TRANSMISSION Alphonse De Muynck, Alost, Belgium Application January 19, 1935, Serial No. 2,523

' In Belgium January 22, 1934 Claims- 74-260) This invention relates to a driving power transmission .with automatically variable speed, in which, for producing a driving momentor couple, use is made of the centrifugal inertia reaction 5 of masses of mercury movable within the planet pinions of an epicyclic gear, of which the driving wheel and the sun-wheel are respectively fixed upon the driving shaft and upon the driven shaft of the apparatus.

'In transmissions of this type known until now, the, drawback exists that vibrations are produced and, moreover, they are not capable of producing a practically constant couple for a considerable series of speeds of rotation of the motor, as it is particularly desirable for transmissions in motorcars.

'lzise'present invention eliminates these drawbac I According to the invention, the vibrations are '2 eliminated when the transmission works as a speed reducer, by arranging the inner blades of the planet pinions, against which the centrifugal inertia ofthe masses of mercury reacts, in such a manner that, notwithstanding the rotation of the blades, which tend to move said masses within the circle described by the axis of the pinion, said masses-will substantially remain outside-said circle, permanently and in all the pinions at the same time. This elimination of noticeable movement of the masses prevents the appreciable .va-

. riations of the inertia moment of thewhole of the transmission and, consequently, the periodical oscillations and vibrations which are caused by F the variations in the known constructions.

' In order to appropriate the transmission'to produce a practically constant couple for variable angular speeds of the motor, the invention provides moreover to construct the inner blades of the planet pinions in such a manner that they. may oscillate or bend, so as to modify the useful capacity of the mercury containing cells bounded bysaid blades and in such a manner that the driving couple, at least starting from the base of average speeds, will only increase slowly, iii-order to allow the reduction of speed at all speeds of the motor normally used. It may be advantageous in this construction with movable blades,

to give to the blades an initial inclination with respect to the radius of the pinion and in the normal direction of rotation thereof, so as to provide-a rate of movability of the blades within The invention will be described with reference to the accompanying drawings illustrating some forms of embodiment of the invention and in such drawings:

Fig. 1 is an axial section through the complete transmission device;

Fig. 2 illustrates a side elevation, on a larger '5' scale, of the planet pinion, from which one flange has been removed to show the inner blades;

Fig.3 is a similar view to that of Fig. 2, with a partial section illustrating a modified form of embodiment of such planet pinion; t

Fig. 4 illustrates an axial section of the planet pinion according to Fig. 3.

Fig. 5 illustrates diagrammatically a further modification, from which Fig. 6 shows a detail.

In Fig. 1, in which the complete apparatus has been illustrated, I designates the driving shaft upon'which is fixed the casing 2 forming 'a flywheel, and which supports, in ball-bearings 3,

the shafts 4 of the planet pinions 5. The latter directly mesh with the sun-pinion 6, fixed to the driven shaft 1, which is itself freely mounted within bearings 8 and 9 of the fly-wheel casing. Each planet pinion '5 forms a cylindrical box, the crown of which is provided inwardly with radial blades In (Fig. 2), constituting with each 25 other cells open in the direction of the center. The pinion box contains a quantity of mercury 12 which, when the fly-wheel 2 rotates at a de termined speed and driving the pinions 5, tends to. accumulate under the effect of centrifugal force, in the outer right-hand sector of the pinion box, as indicated by the interrupted hatchings in Fig. 2.

Presuming that the driven shaft 1 would be motionless or rotate-at a lower speed than the driving shaft I, the planet pinions 5 will rotate about their shafts 4, and their blades 10 will haveto overcome the centrifugal inertia reaction of the-mercury masses which tend to remain lodged in the outer right-hand sector of eachpinion. The rotation of the pinions is thus retarded and a driving couple is produced, which tends to drive the sun-wheel 6 and the charged shaft '1.

As illustrated in Fig. 2, the maximum capacity 5 of the cells II is strictly limited, the free surface limiting the mercury being a cylindrical equipotential surface of balance, the ,center of which starting from the center of the pinion 6, is moved towards the center of the sun-wheel, according 50 to theincrease of the speed reduction. As a consequence, the mercury I2 is caused to flow con- ;tinuously'and progressively from one cell to the other, withoutpbeing submitted to a noticeable movement under the effect of the rotation of the blades and in any case, without any important portion of the mass being drawn within the circle :2: described by the shaft 4 of the planet pinion around the axis of the fly-wheel 2.

It results therefrom that no important modifications are produced in the moment of inertia of the fiy-wheel containing the planet pinions and, consequently, no oscillations or vibrations of said fiy-wheel will result therefrom, as is the case when the masses of mercury are moved completely within the circle :2, as it has been previously proposed in apparatus of this type.

It is easily understood that, as long as the driv ing couple generated by the centrifugal inertia reaction of the masses. Ii is deficient in moving the charged shaft I and the speed driving shaft, the planet pinions rotate about their axes while producing a speed reduction, but after synchronism has been obtained in the speeds of both shafts, the planet pinions become motionless and the whole transmission device rotates as a single block.

However, this means, used with rigid blades fixedly mounted, such as illustrated in the pinion according to Fig. 2, does not permit to produce a practically constant driving couple for the complete series of speeds of the driving shaft I, owing to said steadiness of the blades. Thus a transmission provided with such planet pinions would not give satisfaction when used with motors having considerably variable running speeds, such as the motors of automobiles and the like.

In the modified form of embodiment illustrated in Figs. 3 and 4, the blades I3 of the pinion are arranged so as to be capable of oscillating resiliently under the pressure of the mercury l2. For this purpose, they are provided with a head i4, forming a pivot spindle and lodged in a transverse groove l5 of the crown of the pinion, and their lateral tail portions it are engaged between two teeth I! of a ratchet-wheel l8, fixed at the side of a spring barrel IS. The latter isfreely mounted upon the shaft 4 of the pinion. to which the spiral spring 20 is fixed at 2!. To the spring 20 is given an initial tension which is suflicient to compensate the total thrust of the blades at the determined angular speed taken as a base for the average speeds. I

Moreover, the blades II have a determined initial inclination with respect to the radial direction and in the direction of rotation of -the planet pinion, and their heads ii are off-set so as to limit the deviation of the blades in said direction.

It is obvious that by this arrangementof movable blades, the useful capacity of the cells II is variable according to the inclination of the blades and, inversely, to the rotation speed of the planet pinion. Up to the speed selected as a base for the average speeds, the useful capacity of the cells remains invariable, sbut beyond said speed, the thrust of the mercury upon the blades causes the spring 20 to. give way and the blades oscillate and retain less mercury, as will be well understood by examining the cells at the right-hand side of Flg.'3. By the fact, the quantity of mercury l2a. which is lodged .in the outer left-hand sector of the planet pinion is increased and, by its centrifugal reaction opposite to that of the mercury lodged in the outer right-hand sector, partially neutralizes the reaction generating the driving couple.

. Instead of being rigid and pivoting, the blades l3 may be flexible but fixedly mounted.

According to another possible form of embodiment mentioned, use is made of flexible blades fixedly mounted in the annular casing. In order to enable the blades to have considerable fiexure without interfering with their solidity, each blade for instance is formed with a plurality of thin, elastic, superposed sheets, as illustrated in Fig. 5. All the sheets, except the two outer ones, are provided at the side of their clamping with a number of ports li' (Fig. 6), intended to reduce the resistance to flexion. The front sheet is provided, at its free end, with an extension I, bent over for the purpose of keeping the different sheets forming the blade close together, without preventing however said sheets from sliding the one over the other during their flexure. In order to enhance this movement, use can be made of a very consistent lubricant applied during the mounting of the apparatus between the sheets. The set of sheets are clamped in a groove 2' of the annular casing, and at their edge portion the sheets are provided with a notch 12" (Fig. 6).. In accordance with these notches, the annular casing is provided with a circular groove 3' (Fig. 5), in which is arranged a ring capable of engaging said notches, so that the blades are prevented from sliding out of the curve.

In order to prevent that, at the starting mo-' ment, by considerable fiexion of the blades, the

ous modifications may be provided without departing from the scope of the present invention.

I claim:

1. In an automatically variable speed transmission constituted as an epicyclic gear provided with planet pinions formed as a hollow cylindrical body and having inwardly open cells formed by inner blades with masses of mercury reacting against said blades, the arrangement of said blades so as to be pivotally movable for the purpose of varying the useful capacity of the active cells inversely proportional to the angular speed of the pinions, the whole mass ofmercury acting in apinion remaining constant.

2. In an automatically variable speed, transmissioneonstituted as an epicyclic gear provided with planet pinions formed as a hollow :cylindrical body and having inwardly open cells formed by inner blades with masses of mercury reacting against said blades, the arrangement of said blades so as to be movable for the purpose of varying the useful capacity of the cells inversely proportional to the angular speed of the pinions, resilient means being provided reacting against the mobility of the blades until a predetermined speed is reached by the pinion.

3. In an automatically variable speed trans- Y mission constituted as an epicyclic gear provided 2,061,867 engaging a notched element coaxial to and mova slow variation of capacity of the cells when able with respect to the said crown against the action of resilient means fixed to the shaft of the v pinion.

4. In .an automatically variable speed transmission constituted as an epicyclic gear provided with planet pinions formed as a hollow cylindrical body and having inwardly open cells formed by inner pivotable or flexible blades with masses of mercury reacting against said blades, the arrangement of means capable of imparting to said blades an initial inclination forward to the radial position, for the purpose of having the blades start moving.

5. In an automatically variable speed transmission constituted as an epicyclie gear provided with planet pinions formed as a hollow cylindrical body and having inwardly open cells formed by inner blades with masses of mercury reacting against said blades, thearrangement of flexible blades so that the flexure of said blades varies the useful capacity 01' the active cells inversely proportional to the angular speed of the 'pinions, the whole mass of mercury acting in a pinion remaining constant. a

ALPHONSE DE MUYNCK. 

